Such cutter knives are inserted in cutter devices, which serve for example to cut up meat. The cutter devices have an annular bowl with an approximate semi-circular cross section and are rotatably driven by a motor. The axis of the cutter spindle is located on the radius centerpoint of the bowl, on which cutter spindle are fastened the cutter knives either directly or through mountings. The cutter knives or their mountings are clamped axially with a spacer and clamping rings and an adjusting nut which is screwed on the cutter spindle. For the rotationally fixed connection of the cutter knives or their mountings to the cutter spindle, the latter is as a rule constructed as a hexagon and the cutter knives or their mountings have corresponding openings.
The cutter knives run with a high peripheral speed closely past the bowl wall and are, therefore, exposed to high centrifugal forces. In the case of oppositely positioned double blade knives, which are constructed S-shaped and have two blades and a form-closed receiving hole for the cutter spindle, the centrifugal forces approximately cancel one another. The double blade knives, however, have the disadvantage that the spacing of the knife blades from the cutter bowl enlarges with every regrinding, so that on the one hand the cutting power is reduced due to the enlarged spacing and on the other hand an unfavorable pulling-in condition results during the cutter operation.
Cutter knives having only one blade, which in addition are secured in a mounting, do not have this disadvantage, however, are more difficult to effect a radial adjustment. Moreover, measures are required to prevent with certainty a radial movement of the knives to the outside due to the large centrifugal force. A further problem in the case of cutter knives having only one blade consists in balancing same statically and dynamically with only a little effort, in order to obtain a vibration-free running of the machine.
The basic purpose of the invention is to provide a cutter knife which can be balanced statically and also dynamically perfectly with a little effort, which does not perform any radial outward movements even at high speeds and thus large centrifugal forces and which is inexpensive to manufacture.
A first embodiment of the invention is characterized by securing at least one balancing disk having an opening for receiving the cutter spindle on the cutter knife in the area of the opening for the cutter spindle, the shape, weight and mounting of which are chosen such that the center of gravity of the totality of the cutter knive and the balancing disk lies on the axis of the cutter spindle.
The cutter knife rests with its stop key, which is constructed in an opening on the cutter spindle and is pressed against same through the radial force which acts onto the cutter knife, so that an undesired radial outward movement toward the bowl wall is prevented. The center of gravity of the cutter knife and the balancing disk is moved into the axis of the cutter spindle through the balancing disk which is secured on the cutter knife and through which also extends the cutter spindle, so that an extremely vibration-free run of the cutter spindle is obtained. When the cutter spindle is reground, then the correct spacing of the knife blade from the bowl wall is again created by filing the stop key off for the same amount. The regrinding removes mass on the outside on the knife. However, the radial adjustment effects so to speak automatically a maintaining of the center of gravity, since the knife hub, which is large and heavy, moves in direction of the center of the cutter spindle.
The knife hub is constructed preferably larger than would actually be necessary for the fastening, so that the knife hub also without balancing disks already contributes substantially to the balancing effect.
The cutter knife and the balancing disk are preferably adjustable in their position relative to one another, for example by arranging a slotted hole in the balancing disk or in the cutter knife, through which hole extends a screw, through which both parts can be supported through one another.
It has been proven to be particularly preferable to provide the cutter knife with a balancing disk on its two sides. Each balancing disk is preferably provided with tapped holes, into which threaded pins which serve as balancing weights can be screwed. The tapped holes are arranged preferably concentrically with respect to the opening for receiving the cutter spindle on the balancing disk. By screwing in or removing threaded pins, the cutter knife, including the balancing disk, can be dynamically and statically balanced in a simple and quick manner such that the cutter spindle runs vibration-free also at high speeds. Since each cutter knife is balanced statically and dynamically with its balancing disks, each knife adjustment, namely combination of the angular position of all knife units on the cutter spindle, can be realized while maintaining a low vibration machine run. Thus an optimum combination of the cutting tools is possible by using an inventive cutter knife.
To make reworking of the stop key for the cutter spindle easier, markings can be arranged on said cutter spindle, which are spaced from one another approximately at a distance which during a one-time regrinding the cutter knife must be moved with respect to the cutter spindle.
A second embodiment of the invention is characterized by the knife hub, in the region of which is provided the opening for the cutter spindle, having a heavy balancing part, which is arranged approximately diametrically with respect to the knife blade and the shape, position and weight of which are chosen such that the center of gravity of the cutter knife lies on the axis of the cutter spindle.
Separate balancing disks are not provided in this embodiment, but the mass needed for balancing is provided on the knife itself. It is possible both to design in a correspondingly large-surface construction the knife hub equally thick, as the remainder of the knife, or, however, provide a larger thickness at the hub. Also in the case of a one-piece knife, the mentioned tapped holes and the markings can be provided on the stop key body.